1. Field of the Invention
The present invention relates to a wiping sheet and a process for production thereof, and more particularly to a wiping sheet to be used, in a wet or dry state with or without a chemical solution impregnated thereinto, to wipe out dirt in the kitchen.
2. Description of the Prior Art
Wiping sheet widely used in the past to wipe out dirt in the kitchen is embossed two-ply water-proof paper or nonwoven fabric (called spunlace formed by interlacing fibers), both impregnated with a chemical solution. The chemical solution used for such wiping sheet is composed of alcohol, surfactant, and glycol, so that it easily decomposes oily dirt.
The wiping sheet to be used to wipe out dirt in the kitchen should meet the following conditions.
(a) High bending resistance. Without sufficient bending resistance, the wiping sheet tends to twist or roll during wiping. PA1 (b) High surface frictional strength, which is defined as the number of times required for the sheet to break after rubbing against the surface under a prescribed load. PA1 (c) Specific surface structure suitable for wiping. This is necessary for effective wiping. PA1 (d) Apparent large thickness. A thin wiping sheet is difficult to hold by hand and feels harsh during wiping.
Without sufficient frictional strength, the wiping sheet tends to fluff and break during wiping.
Conventional embossed two-ply water-proof paper as kitchen wiping sheet does not meet all the above-mentioned requirements. It may have its bending resistance in condition (a) increased to some extent. It may have its apparent thickness in condition (d) increased to some extent by embossing and plying. However, it is very poor in surface frictional strength in condition (b) and hence it is liable to break during strong wiping. Also, it has a high surface density contrary to condition (c) and hence is less effective than fiber-interlaced nonwoven fabric.
On the other hand, conventional wiping sheet in the form of fiber-interlaced nonwoven fabric impregnated with a chemical solution does not meet all the above-mentioned requirements either. It may have its thickness in condition (d) increased by increasing its basis weight. It has a surface structure in condition (c) more suitable for wiping than paper, but it is liable to fluffing because it is composed of fibers which are merely interlaced but are not firmly bonded to one another. After several repetitions of wiping, it breaks due to surface fluffing. This is true particularly in the case where it is rubbed against a gas range with charred dirt. In other words, it is also poor in surface frictional strength in condition (b) and hence is poor in wiping performance. Moreover, it is low in bending resistance contrary to condition (a) and hence it is liable to twist and roll during wiping.
As mentioned above, none of conventional wiping sheets meet all the above-mentioned conditions (a),(b),(c) and (d).